Kyukwan Zong

Highly transmissive and conductive poly[(3,4-alkylenedioxy)pyrrole-2,5-diyl](PXDOP) films prepared by air or transition metal catalyzed chemical oxidation

Poly[(3,4-ethylenedioxy)pyrrole-2,5-diyl] n(PEDOP) and poly[(3,4-propylenedioxy)pyrrole-2,5-diyl] n(PProDOP) were synthesized by in situ chemical polymerization yielding highly transmissive, conductive and electroactive thin films. PProDOP coatings exhibit a surface resistivity of 16xa0kΩxa0□−1 at 60% and 58xa0kΩxa0□−1 at 99.9% relative luminance (measured by colorimetry). Many factors were found to impact the formation of the films, including pH, temperature, nature of the dopant ion, and nature of the oxidizing agent. The best combination of dopant ion–oxidant was obtained for anthraquinone-2-sulfonic acid (AQSA)–copper chloride which yielded the most conductive films (σxa0=xa010xa0Sxa0cm−1). A doping level of about 25–30% was determined by X-ray photoelectron spectroscopy (XPS) for PEDOP and PProDOP films. Scanning electron microscopy (SEM) and profilometry indicate homogenous film deposition with total surface coverage attained in films as thin as 40–70xa0nm with a compact and smooth morphology. Spectroelectrochemistry of chemically prepared (oxidized) and subsequently electrochemically reduced PProDOP films showed the disappearance of the π–π* transition, evident as two maxima at 485xa0nm and 518xa0nm upon electrochemical doping. The band gap, measured as the onset of the π–π* transition was 2.2xa0eV. Since the oxidation potential of EDOP is relatively low (+0.6xa0V vs. Ag/Ag+), it was possible to obtain conducting films of PEDOP using air as the oxidizing agent for the polymerization. This result is of particular importance since very few conducting polymers can be obtained by such an environmentally friendly process.

3,4-Alkylenedioxy ring formation via double Mitsunobu reactions: an efficient route for the synthesis of 3,4-ethylenedioxythiophene (EDOT) and 3,4-propylenedioxythiophene (ProDOT) derivatives as monomers for electron-rich conducting polymers

3,4-Alkylenedioxy ring functionalized thiophenes (XDOT’s) have been synthesized by double Mitsunobu reactions to yield precursors to monomers for conjugated and electrically conducting polymers, including the commercially important 3,4-ethylenedioxythiophene (EDOT).

A new method for preparing N-acyloxaziridines via tandem O,N-addition of hydroxamic acids to methyl propiolate

Abstract N-Acyloxaziridines were prepared from a tandem O, N-addition of hydroxamic acids to metyl propiolate in the presence of 4-methyl morpholine as a catalyst im good to excellent yields.

Efficient Synthesis of Dithienogermole (DTG) Derivatives via Olefin Cross-Metathesis

4,4-Bis-(4-pentenyl)-dithieno[3,2-b:2,3-d]germole was synthesized as a functional building block for the efficient preparation of dithienogermole (DTG) derivatives with varying alkyl chain lengths and pendant functionalities in excellent yields. These derivatives were efficiently isolated via olefin cross-metathesis followed by hydrogenation.

Study of a new crown-ether derivatized polydioxypyrrole

Abstract A new fused tetramethyl substituted 14-crown-4 3,4-pyrrole (TMC-DOP) has been polymerized and the redox switching properties of the resultant polymer investigated such as its possibility of lithium ion sensing. Especially, interesting redox properties have been obtained when the polymerization is carried out galvanostatically at a low current density of less than 50xa0μAxa0cm −2 . In this instance, two redox processes labeled α ( E 0 ∼−0.65xa0V) and β ( E 0 ∼+0.15xa0V) are reproducibly observed. A cation sensing study revealed a clear cyclic voltammetric response due to a β→α process conversion with a slightly higher sensitivity for lithium ions when compared to sodium ions. The poly(TMC-DOP) exhibited a strong electrochromic response, changing from yellow at −0.7xa0V to highly transmissive and color neutral at +0.2xa0V indicating possible ionochromic behavior upon optimization of the electrochemical detection load.